In an environment in which original sounds are emanated from a variety of sound sources (e.g., a violin, a plano, a human voice, etc.), a listener may perceive a variety of audio cues related to directions and depths of the sound sources in the original sounds. These audio cues enable the listener to perceive/determine approximate spatial locations (e.g., approximately 15-20 feet away, slightly to the right) of the sound sources.
An audio system that uses fixed-position speakers to reproduce sounds recorded from original sounds typically cannot provide adequate audio cues that exist in the original sounds. This is true even if multiple speaker channels (e.g., left front, center front, right front, left back, and right back) are used. Such an audio system may reproduce only one or more directional audio cues, for example, by controlling relative sound output levels from the multiple speaker channels. Located in an optimal listening position relative to the configuration of the multiple speaker channels, the listener may be able to perceive, based on the directional audio cues in the reproduced sounds, from which direction a particular sound may likely come. However, the listener still will not experience a lively feeling of being in an environment in which the original sounds were emanated because the reproduced sounds still fail to adequately convey depth information of the sound sources to the listener. These problems may be exacerbated if the listening space is not ideal, but rather with sound reflections and multi-channel cross talk between different sound channels.
The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualify as prior art merely by virtue of their inclusion in this section. Similarly, issues identified with respect to one or more approaches should not assume to have been recognized in any prior art on the basis of this section, unless otherwise indicated.